


Convection

by Unladylike (Lady_Kit)



Series: Generating heat [1]
Category: Undertale (Video Game)
Genre: Because of Heat, Consent issues touched on, Dom Papyrus, Genitals mentioned but none appear in-fic, M/M, Mating Cycles/In Heat, Mildly Dubious Consent, No Genitals, Otherwise it’s pretty consensual, Self-Esteem Issues, Soul Sex, sub Red
Language: English
Status: Completed
Published: 2020-02-14
Updated: 2020-02-14
Packaged: 2021-02-22 16:14:54
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,088
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22718740
Author URL: https://archiveofourown.org/users/Lady_Kit/pseuds/Unladylike
Summary: Red doesn’t know what’s wrong with him.Papyrus does, and he’s happy to help.
Relationships: CherryBlossom - Relationship, Papyrus/Sans (Undertale)
Series: Generating heat [1]
Series URL: https://archiveofourown.org/series/1648246
Comments: 11
Kudos: 134





	Convection

**Author's Note:**

> A/N: I feel I should mention that this is not especially graphic in the conventional sense. There are no genitals on display here, but it is pretty obviously sexual despite that. If anyone feels I missed a tag, please let me know—I had a hard time tagging this properly.

“What the fuck is wrong with you, runt?”

Red glared at Boss, flipping him off. “nuthin’. fuck off.”

“Were you at Grillby’s last night?”

Red groaned, pillowing his skull on his arms. “‘m fine. ‘s not a hangover.”

Boss grunted skeptically, then pressed the back of his hand to Red’s skull. “Hmmm. You’re not fine. Not with a temperature like that. What are you other symptoms?”

“well...i got this pain in my ass that won’t go away. think ya could help with that?”

Boss just frowned, ignoring the barb. “You’re staying here today.“

“aw, boss—c’mon!” 

Firmly, Boss nodded to himself. “Yes. You’re staying here. The others won’t appreciate it if you get them sick.” He hefted Red up, lifting him by the back of his jacket and dragging him back upstairs. 

Red didn’t try to fight him, but he didn’t help either, just let his brother muscle him back into his bedroom. “you jus’ don’t wan’ me ‘round while ya flirt with rus.”

Boss’ cheekbones heated. “I am not—!” He cleared his throat, gruffly tugging Red’s jacket off. “I do not flirt. With anyone. Wether or not you’re there.”

“uh-huh. yeah. sure—“

Leaning down, he caught Red’s chin and looked into his sockets. “Runt, I’m only going to say this once, so you had better treasure the memory—get back into bed and rest. I’ll make soup for you when I get back.”

“gee, boss. i must really look like shit if yer sayin’ that.”

“You do. Bed—now.”

Grumbling, Red flipped him off again but stumbled back into bed. Boss shut off the lights and shut the door behind him. The sheets felt cool on his heated bones, and Red sighed softly, momentarily relieved. He just felt so fucking hot. Awkwardly, he shimmied his hips and tugged at his shorts until he could kick free of them. Then he pulled at his shirt and tossed it aside. Sweat beaded on his bones, and mana flushed his bones a pale red.

He groaned, tucking his skull against the pillow. Stars, he was hungry. But he did not want to get up to eat. He didn’t want to move from this spot. He tugged at the sheets and the blankets, pulling them free so he could fit them around himself in a loose circle. That felt right. Satisfying. So he punched the pillows until they were in just the right place too, curling in on himself to find a comfortable place in the nest of bedding.

He was still hungry. He wasn’t sure what he wanted, though. Something sweet and salty, probably. Definitely something bad for him. He still didn’t feel like moving, though.

Red sighed into the blankets, running his fingers over the sheets. They felt soft and smooth, almost silky against his bones. They felt nice. Actually, despite the heat and the hunger, he felt nice. He certainly didn’t feel sick. Not really. He felt kind of...floaty. 

It wasn’t a bad feeling, but fear started to claw at his soul, puncturing the good, floaty feelings. He didn’t know why he felt like this. He hadn’t taken anything—not lately, at least—but he definitely didn’t feel right. Had he been drugged? By who? And when? They were on the Surface now—things like this weren’t supposed to happen any more!

He struggled upright, his limbs heavy. Stars, he was hot. Was it mana or magma in his bones? And when had his hunger morphed into something else entirely? His soul was starting to itch and ache, and it felt strangely heavy. And hot. Stars above, it felt like it was burning—!

“CHERRY?!”

Red froze, hearing that. Papyrus. It could only be Papyrus. With a wet, nearly pornographic sound, his soul popped into existence, settling behind his ribcage and weeping a clear, red-tinged fluid. 

He gasped and clutched at a pillow, trying to hide himself. “don’—don’t come in here! sumthin’s wrong. real...real wrong.”

“CHERRY? ARE YOU ALRIGHT?”

Red bit down on his fingers and squeezed his legs together. His voice...stars, Papyrus’ voice flowed over him like honey, making his soul drip. Mana was starting to gather in his joints, too, blossoming into sensitive nodes. “CHERRY?” He knocked on the door. “ARE YOU IN THERE?”

“yes.” Despite himself, it came out as a throaty moan. 

For a moment, Papyrus was silent, and Red knew that he’d heard. Shame caused his bones to flush a deeper red, even as he imagined Papyrus pushing the door open and stroking his heated bones, grasping his dripping soul, and—

Another rush of mana caused his nodes to swell and his soul to drip. He must have whimpered because Papyrus asked, “Cherry?” Contrary to Red’s fantasy, he didn’t even crack the door. Red bit his fingers even harder, trying not to whine at the shift in his voice. “It sounds like you might...might be in. Well. Um. You know. Is there someone I can call for you?”

“what?”

“You’re, um. It sounds as-as if you might...might be in. In...well. In heat. Do you—? Do you have an, um...a special friend?“

“what?” he asked, hoarse and desperate. Stars, what was he trying to say? Red might actually be dying from pure arousal, and Papyrus was asking about friends?

Papyrus cleared his throat and cracked the door open, so his voice could carry more clearly. He didn’t peer inside, but Red could see his long fingers wrapped around the door, and now all he could imagine was those same fingers on his soul, around his cock, in his pussy. He couldn’t decide which he wanted more. “—intimate partner? You know—someone you can spend your heat with?”

“my what?!”

“Cherry, I don’t know how to be clearer! You are obviously in heat, and it would be a much better experience for you if you had someone to see you through it! Now—can I call someone for you?” Under his breath, he added, “I don’t know why Edgy-me said you were sick. Honestly, you Fell-verse monsters are so secretive, it’s unhealthy!”

Red couldn’t help his wry smile, hearing the impatient note in his voice. “sorry, creampuff, but i don’t know what yer talkin’ about. but—“ he clutched the pillow, suppressing a moan. “i don’ think ya wanna stick ‘round fer this.”

Papyrus was silent, and Red wasn’t sure what to read into that silence. Until he said, in a horrified whisper, “You don’t know what heat is?”

“should i?”

Papyrus didn’t say anything for a moment. Then he took a deep breath and said, firmly, “We’ll talk about it later. For now, I imagine you’re, um, quite uncomfortable.” Red shut his sockets, trying not to laugh.

“yeah,” he rasped, “ya could say tha’.”

“Well. The best way to take care of it is to have a-a trusted friend help! Is there anyone that I can call for you?”

He hesitated. “my soul’s out, an’ i can’t get it ta go ‘way. ‘s a short list ‘a people i trust with my soul, an’ i don’ exac’ly wan’ boss ta see me like this.”

“Do you trust me?”

It took a moment to process the question, but when he did, it sent a bolt of pure need down his spine. “fuck,” he gasped, doubling over the pillow. “c-creampuff, i don’ think ya know what yer sayin’.”

“Red, I know what heat is. I’ve gone through it myself a few times.” He said it loftily, but the idea of Papyrus doubled over with desperate desire had Red salivating. “I know what I’m offering. I want to know if you’re willing to accept my help.”

On another day, Red would have refused. Not because he didn’t want Papyrus, but because Papyrus deserved better than a fuck-up like him. Now, though, with his bones burning and his soul dripping with desire, he couldn’t deny himself. “yes, stars, yes. fuck, creampuff, please—“

Papyrus was through the door in an instant, and he was sliding his gloves off. Red looked up at him, painfully aware of the pathetic picture he made right now. Sweat-soaked and needy, hugging a pillow already slick with mana from his dripping soul. If he’d ever dreamed of actually making a move on Papyrus, he certainly hadn’t pictured it like this. Ashamed, Red looked away, his fevered bones shivering. “s-sorry,” he started to say, “ya don’ gotta—don’ gotta do nuthin’. if ya...if ya don’ wanna.”

Papyrus knelt in front of him, looming. He cupped Red’s cheekbone, running his thumb down his jaw. It was a gentle, delicate touch, but it knocked the breath from Red’s ribcage and set his soul hammering. “None of that, now. I’m here to look after you, so hush.” He climbed into the nest beside him and pulled Red into his lap. 

“wait—yer pants!” Stars, he was disgusting—he was going to get spent mana all over Papyrus. Even if there was some appeal in marking him so intimately, it was dampened by knowing Papyrus would only be disgusted by him.

“Shhh, it’s alright, Cherry.” He stroked along Red’s spine, massaging the vertebrae. “I don’t mind. You are more important than any piece of clothing. Just relax.”

Red’s grip on the pillow tightened. “yeah? ya might change yer mind in the mornin’.” Fear shivered through him, sparked by what was meant to be a pithy reply. Papyrus’ hands stuttered over his bones, and Red braced himself. Papyrus was going to change his mind. He had to realize who— _(“fell-verse trash”)_ —he was touching in just a minute—

Papyrus’s hands caught his spine in a firm grip, knuckling the cartilage between each vertebra. Red buried his face in the pillow, trying to silence a moan. His fingers flexed. Yes, the steadying touch was nice, but he needed more. It wasn’t enough, but he couldn’t expect, couldn’t ask for—

His vision whited out when Papyrus’ clever hands found the node at the base of his neck, engorged with mana and pulsing with heat. His breath caught in his chest, the pleasure so intense it was indistinguishable from pain. Then, all at once, his soul contracted—hard—and a fresh gush of mana welled from the base, spattering his ribcage and pillow. He gasped, able to breathe again, and cried out when Papyrus pumped his lumbar spine.

“Is that a little better?”

Mute, Red nodded, trying to catch his breath. “y-yeah. uh, creampuff? where’d ya learn ta do tha’?”

“Cherry! I am a gentleman! I do not kiss—“ A slow swipe over his upper sacrum. The words and sensation leading Red to envision it was Papyrus’ mouth on his sacrum instead of his skillful fingers. “—and tell.” The words were breathed over his jawbone, reassurance and seduction all at once. “Are you ready for another orgasm?”

Red’s soul was still pounding from the last. “tha’ what tha’ was? wasn’ sure. ya don’ hafta be so gentle with me. ain’t gonna break.”

Papyrus’ hands stuttered again, and Red was sure he’d scared him off. Then he heard Papyrus swallow hard, and felt the heat between his thighs. “You are.” A steadying breath as Papyrus regained his confidence. “Not wholly yourself right now, Cherry. Perhaps another time.”

“don’ make promises ya ain’t gonna keep.” There was pressure on his sacrum, right over another swollen node at the base of his coccyx. He sucked air in through his teeth. “fuck! fuck—what’re ya—?”

“You are very talkative.”

Through clenched teeth, he said, “yeah? one ‘a my b-better qualities. big mouth. wanna give it a try?”

He pinched the node between his fingers, and Red made an undignified sound of need and pain. Fuck if it didn’t get his soul dripping all over again. “Maybe later.” He rolled the node between his fingers, wringing a sob from Red. “Are you ready?”

Tears were welling in his sockets. “please, pap, please—“

He ran his thumb over the node as Red begged, bringing him to another peak. Red breathed through it this time. His mana lines prickled, and his soul clenched hard. On a hard gasp, he came, babbling nonsense. 

Papyrus held him through it, resting his chin on his shoulder and murmuring reassurances. Slowly, Red’s soul steadied and the pleasure tapered off. His sockets drifted closed and he leaned against Papyrus, allowing him to support him. “How do you feel now?” Sockets shut, Red tried to find something pithy to say, but his bones had gone limp and loose, and he was having trouble gathering his thoughts. “Cherry?”

“good,” he slurred, fingers kneading at the pillow. “tired. kinda sore ‘round my joints.” His soul squeezed. “heh. hungry.”

“Good. Let’s get you cleaned up a bit, and then we’ll get you fed. Does that sound good?”

He just nodded dimly, pliant and happy to let Papyrus take the lead. Papyrus stood and cradled him against his chest, carrying him to the bathroom. When he tried to pull the pillow away, though, Red gripped it harder. Papyrus stopped and knelt down. “Cherry? Is something wrong?”

He looked away, feeling small and gross again. “my soul’s still out.”

Papyrus’ sockets widened in understanding. He sat down on the bathroom floor, and Red cringed, seeing the spent mana smeared on his bones and his clothes. “It won’t go away until your heat’s over,” Papyrus said, running a thumb over the back of his hand and wrist. “Do you want a shirt? Something to cover your ribcage?”

Red’s skull jerked up. “‘s not over?”

“Heat usually lasts about a week.”

“a week?!” His voice cracked on the last syllable. 

“I’ll stay with you. Or call someone else if you want.” His hand was steady on his wrist, the thumb rubbing soothing circles in his carpals. “No matter what, I will do my best to make sure this is a positive experience for you.” He beamed, but Red only hugged the pillow tighter.

“how c’n it be ‘positive’, huh?”

Something shifted in Papyrus’ smile, and it caused Red’s soul to clench in a mix of apprehension and anticipation. “May I show you?”

Red hesitated, but Papyrus’ hand steadied him, and his grin shot a bolt of pure need down his spine. The oversensitive nodes at his joints pulsed. He swallowed and nodded. 

“Excellent!” 

He lifted Red up to carry him into the shower and peeled his pants off. He tugged at the corner of the pillow gently. Getting the message, Red took a steadying breath and set it aside, his fingers shaking. “Good,” Papyrus murmured, scratching along his cervical vertebrae and coronal suture. It startled a purr from Red’s chest.  


He flushed in embarrassment, but Papyrus pulled him against his chest, so Red could hear his answering purr. Red’s sockets shut slowly. That was nice, he had to admit, feeling Papyrus shift as he shimmied out of his clothes. He left his unitard on, though, and Red stifled a brief pang of disappointment. He wanted to feel bare bone against his, the thin spandex an unwanted barrier. 

Before he had the chance to dwell on that, Papyrus turned the water on, and the warm water washed over him. He shuddered, thinking that a cold shower might be a better choice, but then Papyrus’ hands were skating over his ribs. He thumbed along his sternum, lightly scratching between each rib-bone. Red moaned, magic flooding his over-sensitized nodes. “pap—“ His voice was weak and wavery.

Papyrus hushed him, hands sliding down his spine to his pelvis. He simply rested his hands oh Red’s hips, rubbing soothing circles into his hipbones. “It’s okay, Cherry. I’ve got you. Let go.”

He shook his head, and Papyrus pulled him flush against him, resting his chin on Red’s skull. A whimper escaped him. “pap, i can’t.”

“You can. With a little help.” He tapped lightly on Red’s ribcage. “May I?”

Red looked down, swallowing hard. His soul glowed feverishly and slick magic dripped from the crease. It contracted, and he stifled a whimper, feeling the deep-seated ache. The pain faded when his soul relaxed, but it continued to hover on the edge of his awareness. “why’s it—? why’s it hurt?” 

Papyrus rubbed a soothing hand over his sternum. “Magic flux, I’m told. Physical contact helps. May I?”

Still hesitant, Red looked down, fists clenched. His soul contracted again, a longer, more drawn out cramp. He inhaled sharply and squeezed his sockets shut. It wasn’t unbearable. It wasn’t torturous; he’d definitely had worse. But it was unpleasant, and the promise of relief was temptation itself.

_ Papyrus’ hands on his soul soothing the ache, projecting reassurance and affection and— _

He swallowed, feeling Papyrus’ soft projections. “no fair,” he mumbled, “tha’s cheatin’.”

“I’m only trying to help, Cherry. Remember, you’re the one in control here. We’ll only go as far as you want.”

Soul still cramping, he asked, “will ya take this off?” He tugged at the unitard.

Papyrus hesitated, then nodded. “If that’s what you want.”

He stepped out of the shower and wriggled out of the wet garment. A striptease it was not, but the sight nonetheless caused Red’s soul to cramp and his nodes to swell uncomfortably. When Papyrus straightened, Red realized why Papyrus had been reluctant before. Pale orange magic had gathered at his joints too, and it swirled in the cradle of his pelvis, still unformed. He looked away, blushing. Uncertain since the first time he’d offered his help.

“I. Well. Um. I want to-to assure you that I will not take advantage of you while you are in heat, Cherry.” He nodded firmly. “However I can help, I will, but it’s not for my own gratification—“

“ya wan’ me?”

The blush deepened and spread across his sternum. “That is. That is not important right...right now. I am much more concerned about—“

“say it, creampuff.” If Red thought his bones were fevered before, now it felt like he was on fire. As the cramping in his soul blossomed into need, he decided he wouldn’t mind letting that fire consume him. “say ya wan’ me.”

Papyrus looked at him, seeing the change in his gaze and demeanor. “I want you, Red.”

“then what the fuck are ya standin’ over there fer? c’mere.”

He pulled him into the tub and they both stumbled. 

“Cherry! Please—this is unsafe!”

Red didn’t care. He _wanted_ now, and the whole of that need bore down on him, no longer held back by shame. He knelt down, barely feeling the ache in his patellae, and lapped at Papyrus’ pubic symphysis. The first taste of magic sent his soul soaring, but it only opened a yawning, aching need for more. His fingers tightened around Papyrus’ thighs, pushing them apart—and causing him to flail, his balance lost. Papyrus tumbled to the floor and took Red down with him, both miraculously uninjured. 

Red still didn’t care. He again grabbed Papyrus’ thighs and pushedthem up, bending him near in half. Papyrus grunted, stunned. Again, Red dove for the place between his femurs, lapping at the mana gathered there. A hand clutched at the back of his neck, and Red moaned, a litany of promises running through his mind— _promise ta take care ‘a ya, creampuff, promise ta make ya feel good, won’ regret this, won’ ever regret this_ —

The hand tightened, finding an over-sensitized node. “Red, that is enough!” For just a moment, he froze, afraid Boss had returned and found them like this, but looking up, he could see it was Papyrus that had spoken. “Cherry,” he said, gentling his tone, “I’m not opposed to this, but I think we can find a more comfortable position.” He started to shift, but Red tightened his grip, a soft growl vibrating through him.  


Still gentle, Papyrus ran a hand down the back of his skull. “I’m not leaving you.” He pet along Red’s jawbone, slipping a pair of long fingers past his sharp teeth. Red turned his skull and took them deeper, slicking them with magic. 

Papyrus shifted beneath him. Red clutched at him, but he was drawing closer and not further away, so that was okay. He pulled his hand free from Red’s mouth and asked, “Can I touch your soul?” 

Even through the haze of need, Red hesitated. Those gentle projections began again—/ safety / security / stability / affection /—but it was the undercurrent of suppressed desire that truly convinced him. “yeah. ya can.”

“Thank you.” Papyrus kissed him then—their first. Warm water slicked their bones, and the air grew thick as steam condensed around them. Red groaned into it, relaxing into Papyrus’ embrace and savoring the taste of him, the scent of his magic.

He was so focused on the tongue in his mouth and the hand on his jaw, he didn’t notice the other hand slipping past his ribcage. Until a magic-slick finger pressed into the crease of his over-sensitive soul. He wailed, and Papyrus pulled back just enough to murmur sweetly into his acoustic meatus. The words themselves were a muddle, lost as Red was consumed by his Intent. 

There was more than pleasure in the touch. There was also the promise of safety and love. It was hypnotic. Intoxicating. Red burrowed into Papyrus’ hold, feeling as if he just couldn’t get close enough. 

He didn’t realize there were tears in his sockets until Papyrus wiped them away. 

-

The world took on a pleasurable haze after that. It was a lot like being drunk or drugged, but he felt safe enough to luxuriate in the feeling rather than fight against it. Papyrus was a steadying presence, protective and constant. His gentle hands played over Red’s bones, the two of them like musician and instrument. 

He was faintly aware of being dried off, but he protested when Papyrus tried to re-dress them. He burrowed closer and hooked his fingers through Papyrus’ ribcage, savoring the sensation of bone on bone. Placidly, Papyrus pet along his spine and agreed that they didn’t have to get dressed if it upset him that much.

Papyrus brought him back to the bedroom, and Red allowed him to leave only because he promised to return with food. When he returned, Red pulled him into the nest of blankets and wrapped them both up. The fire in his bones had settled into a steady warmth that left him pleasantly sleepy and relaxed.

Papyrus pressed a water bottle into his hands. He guzzled it down, surprised to realize he was so thirsty. He purred when Papyrus praised him for it. The food he brought was simple—apples and wedges of cheese, bread and peanut butter—but filling, and something in Red trilled in pleasure at that. He made sure Papyrus ate too, pressing him when he protested that he wasn’t hungry. When the food was gone, Red pushed him back into the nest and climbed on top of him.

This felt good, he thought, resting atop Papyrus. It felt right. Everything felt nice, the world’s edges temporarily dulled to something softer and sweeter. He shut his sockets, happy to rest like this for a while.

Before he could drift off, his soul clenched hard, cramping painfully. His brow-bones furrowed and his fists clenched closed as he suppressed a pained moan. The cramp persisted, a constant ache, and he shook his head. This wasn’t fair! He just wanted to _sleep_! 

A gentle hand wrapped around his soul, projecting softly. “Let me help.” Red nodded his agreement. He really wasn’t interested in another orgasm. He just wanted to rest, but he was willing to do whatever was necessary to get his soul to settle.

As Papyrus’ thumb rubbed soothing circles into his soul’s surface, though, he realized there was something different in his Intent this time. Rather than pleasure, there was peace in his touch. His fingers massaged the surface of his soul, soothing away the ache without exciting him further. 

“thanks.” Red’s voice was a soft rasp. He settled against Papyrus’ chest, no longer disturbed by the pain.  


“Of course! I said I’d look after you this week, didn’t I?”

Red nodded dimly, already drifting off. Somehow, he’d assumed that only meant Papyrus would help him out sexually. He hadn’t thought it would mean moments like this.

He must have said something aloud, because Papyrus chuckled softly and said, “Oh, Cherry. Of course I’d be with you for this too. These are the best parts of being in heat.” A gentle hand scratched along his coronal suture. “And of helping someone through theirs, of course.”

Warm, safe, and sated, Red could only agree. 

**Author's Note:**

> Because sometimes you just want a (semi-)conventional heatfic, without all the unnecessary angst.
> 
> ...I might do a second chapter with Edge.


End file.
